Profile grinding or polishing machine



Sept 7, 1954 F. T. DYER ETAL PROFILE GRINDING OR POLISHING MACHINE 5Sheets-Sheet 1 Filed Oct. 16, 1952 Inventors Frederm 7? 0g flag mono! HAttorney Sept. 7, 1954 F. 'r. DYER ET AL PROFILE GRINDING OR POLISHINGMACHINE 5 Sheets-Sheet 2 Filed Oct. 16, 1952 a Fry .m m e t i A mp4 d 4%ea Q ept 7, 1 F. T. DYER ETAL PROFILE GRINDING OR POLISHING MACHINE 5Sheets-Sheet 3 Filed Oct. 16, 1952 F/G'4 30 2 50/ 375 {g 57/ 574 Sept.7, 1954 F. T. DYEJR ET AL 2,638,212

PROFILE GRINDING OR iOLISHING MACHINE Filed Oct. 16, l952 5 Sheets-Sheet5 I Inventors ire derzc 7 er flay/wand; ea (2 9 Attorney Patented Sept.7, 1954 PROFILE GRINDING OR POLISHING NIACHINE Frederic Thomas Dyer andRaymond Herbert Revett, Ipswich, England, assignors to Ran- .somes Sims& Jefieries, Limited, Ipswich, England, a British company ApplicationOctober 16, 1952, Serial No. 315,142

Claims priority, application Great Britain October 19, 1951 4 Claims.

The invention relates to a profile grinding or polishing machine of thecharacter described in the specification of U. S. Patent No. 2,585,376and consists in improvements in or modifications of the means foreffecting and controlling the opera-- tion of the cross feed carriage.

The objects are to ensure smooth and accurate operation by simpler meansthan a lead screw driven by a variable speed gear box and motor, andalso to permitof a greater range and more flexible control of speedvariation during feeding, and a rapid return of the cross feed carriage.

The invention consists in the provision of a hydraulic cylinder foradvancing and returning the cross feed carriage, and of a control valve,for

controlling the supply and exhaust of pressure fluid to and from thehydraulic cylinder, the control valve being operable by hand to startand stop the operation of the cross feed carriage when required, andalso operable automatically to stop the operation at the end of eachfeeding and return stroke of the cross-feed carriage.

A valve is also preferably provided to work in conjunction with thecontrol valve to regulate the flow of exhaust from the hydrauliccylinder during the advancingor feeding stroke of the cross feedcarriage for the purpose of regulating the rate of feed.

The control valve is preferably such that it has two exhaust ports foralternate use during the feeding and return strokes of the cross feedcarriage, one port being connected with the regulating valve during theadvancing or feeding stroke of the cross feed carriage, and the otherport being connected with a gate valve or the like permitting of a freeflow to a sump during the return stroke of the cross feed carriage toeffect a quick return. i

The regulating valve is preferably automatically operated by a cam onthe cross feed carriage so as to vary the outflow of exhaust fluidduring the feeding of the cross feedcarriage. Theregulating valve isalso adapted to be adjusted or set by hand so that the effective area ofthe exhaust outlet controlled by it can be accurately determined. l y

In the accompanying drawings:

Figures 1 and 2 are respectively a front and side elevation of agrinding and polishing machine according to the invention;

Figure 3 is a side view of the attachment of the piston rod of thecross-feed hydraulic cylinder to the cross-feed carriage part of whichis shown in section;

Figured is a longitudinal sectional elevation of the control valve forthe cross feed hydraulic cylinder;

Figures 5 and 6 are respectively a side elevation and a plan of thespeed control valve;

Figure '7 is a front sectional elevation of the speed control valve onVII-VII, Figure 6;

Figure 8 is a sectional plan on VIIIVIII, Figure 5;

Figure 9 is a diagrammatic side view of the hand and automatic means foroperating th stop and start valve; and,

Figure 10 is a flow diagram.

The machine illustrated by Figures 1 and 2 is of the character describedin the specification hereinbefore referred to and for convenience someof the corresponding characteristic parts are indicated by similarreference numerals to those in the drawings accompanying thatspecification.

Briefly the machine comprises a grinding wheel fixed on a spindle 2which is mounted to rotate in a bearing housing 3 pivotally supported ontrunnions 4 in a crotch 5 adapted to be raised and lowered on astationary column 8 so as to vary the height of the pivotal support ofthe grinding wheel spindle. The spindle 2 is normally free to oscillateabout its pivotal axis but means are provided for swinging the spindlewith its grinding wheel up into an inoperative position at thecompletion of a grinding operation, and for lowering it again asrequired.

A work piece to be ground or polished indicated in dotted lines at isclamped on a work table 3 mounted to oscillate on trunnions 3E supportedby brackets 3? on a traversing table 38 which reciprocates on slideways39 and rollers 40 on a cross feed carriage 4 l.

The work table is tilted up and down by hydraulic cylinders. In themachine described in the specification hereinbefore referred to thesewere single acting cylinders, but in the present instance double actinghydraulic cylinders 303 are indicated. They are pivotally mounted ontrunnions 3% on brackets 305 fixed on the brackets 37, and have pistonrods 386 pivotally con nected at it! to levers $08 fixed on thetrunnions 393 of the work table 34.

The traversing table 38 is reciprocated by a double acting hydrauliccylinder 42 as described in the specification hereinbefore referred toand during the reciprocations or traversing movements of the table 38,the Work table 34 is tilted up and down by the hydraulic cylinders 303the supply and exhaust of pressure fluid to and from which arecontrolled by a control valve 3| l which comprises a ported valve casing3|3 fitted internally with a piston valve having an operating plunger339 having a roller 340. running on a cam bar 34L The cam bar 34| issupported on rods 342 carried in guides 343 on the cross feed carriage4|, the rods having rollers 344 on their lower ends running on rails 345on the machine base 85.

The control valve casing 3|3 is carried on a bracket 3|2 sliding up anddown in guides on brackets 3|9 fixed on a cross bar 320 supported at itsends on the brackets 31 on the traversing table 38. The bracket 3|2 isconnected by links 323 to an arm 325 on the work table.

The result is that as the traversing carriage reciprocates to presentthe work piece on the work table to the grinding wheel, the work tableis tilted up and down to maintain the surface to be ground normal to thegrinding wheel which makes mutual movements as explained in thespecification hereinbefore referred to. The mechanism above describeddoes not form an essential'part of the present invention and is morefully described in the specification of (to-pending application SerialNo. 315,141, filed on even date herewith, and the above briefdescription is only given for convenience in understanding the characterof the machine.

In the U. S; specification No. 2,585,376, mechanism is described forslowly advancing and more quickly retracting the cross feed carriage 4|,but improved means for effecting this according to the present inventionwill now be described.

The cross feed carriage 4| is mounted to slide on slideways 85 on thestationary machine base 55. It is reciprocated on these slideways by adoubleacting hydraulic cylinder 390 fixed on the base 65. The piston rodI of the hydraulic cylinder 300 is attached at its outer end to abracket 302 fixed on the underside of the cross feed carriage 4|. Thesupply and exhaust of pressure fluid to opposite ends of the cylinder300 is effected by pipes SH and 312 connected with a control valve 400.It comprises a valve casing 313, Figure 4, having ports 314 and 315 withwhich the pipes 3H and 312 are respectively connected. It also has aninlet or supply port 316, and two exhaust ports 311 and 318.

A supply pipe 319 is connected with the port 318', and two exhaust pipes380 and 38| are respectively connected with the exhaust ports 311 and318. I

A piston valve 382 controls these ports. It protrudes from the ends ofthe valve casing, and inside the casing it has a central piston 383 forcontrolling the supply port 316, and two outer pistons 384 and 385 forrespectively controlling the exhaust ports 311 and 318.

The protruding ends of the piston valve 382, as explained later on,engage with tappets 386 and 381 which are fixed on a push rod 388,mounted to slide on parts 389 and 390 of the base 55.

The control valve casing 313 is fixed by a bracket 39!, Figure 1, to thebase 35.

The exhaust pipe 380 is connected to an exhaust regulating valve 392 bywhich the rate of outfiow of pressure fluid can be controlled to varythe speed of the cross feed carriage 4| when advancing under theinfiuence of the hydraulic cylinder 300. The exhaust pipe 38| on thecontrary is fitted with an ordinary gate valve 393, Figure 10, so thatpressure fluid in the exhaust pipe 38| can flow freely to a sump I90,and consequently allow the hydraulic cylinder 300 to effect a quickreturn of the cross feed carriage 4|.

The regulating valve 392, which may be conveniently termed a speedcontrol valve,.comprises a valve' casing 394, Figures 6 and 7, having aninlet port 395 with which the exhaust pipe 380 is connected, and anoutlet port 396 connected by a pipe 391 to the sump I90, Figure 10.

A. piston valve 398 has a piston 500 for controlling the outlet port 396and a piston 399 for balancing internal. pressure only.

The piston valve 398 protrudes from both ends of the casing 394. and isurged upwardly by a helical spring 40L. The upper end of the pistonvalve 398 is in contact with a lever 402 which has a fulcrum pin 403 atone end and a roller 40.4 at the other end for engagement with a cam 405which is fixed on the cross feed carriage 4| (Figure 2). The fulcrum pin403 is supported in a bearing bracket 393 fixed on a plate 4| I which issecured to the. machine base 85. The valve piston 500 has a slot 405-which tapers downwardly so that as the piston valve 398' is depressedthe amount to which the slot 406 is opened tothe outlet port 396 isincreased. In

- orderto enable the effective area of the slot to be varied or adjustedaccurately by hand, and thereby to regulate the outflow of exhaust fluidandconsequently regulate the feeding movement of the cross feed carriage4|, means are provided for'partially rotating the piston valve 398relatively to the casing 394, such means being adapted to-holdthe pistonvalve 390 against rotation after adjustment and yet allowit to slide upand down in the casing.

These regulating means comprise a lever 401 on the lower end of thepiston valve 398. The lever has a key 408 which enters a slot 409 in thepiston valve 398', the slot being deeper than the key so that the pistonvalve can rise and fall relatively to the key.

The lever 401 is mounted in a forked bracket 4|0 which is fixed to plate4| on which the casing 394 of the regulating valve 392 is also mounted.

The outer end of the lever 40'! is forked and supports apin or trunnion3. A rod 4|4 has one end fixed in the trunnion M3 and is screw threadedto receive a regulating nut 4|5 which has a cylindrical extension 4|0mounted to rotate in a bracket 4 I1 fixed on the plate 4 H. The nut M5is prevented from sliding by balls 4|8 which engage in a groove 4 9 inthe nut, the balls being held in position by plugs 420, Figure '1.

Rotation of the nut M5 in one direction or the other effects relativerotation of the piston valve 398 in the casing 394 and consequentlyalters the position of the slot 406 in the piston 500 relatively to theoutlet port 396 and thereby determines the effective area of the slotfor the outflow of exhaust fluid.

The plate 4|'|' is fixed to the machine base 65 and, as shown in Figure2, in such a position that the roller 404 on the lever 402 can beoperated by the cam 405 to regulate the flow of exhaust fiuid from thecontrol valve 400 during the relatively slow advancing or feeding strokeof the cross feed carriage 4|.

As mentioned above, the exhaust pipe 380 is only used during theadvancing or feeding stroke of the cross feed carriage 4| the otherexhaust pipe 38| being used during the return stroke of the cross feedcarriage when the free flow through the gate valve 393 is possible toallow a quick return of the carriage.

As shown more clearly in Figure 9, a hand opcrating lever 42I, pivotedto the base 65 on a pivot pin 423 and pivotally connected by a pin 422to the push rod 388, enables the control valve 400 to be operated byhand at any time to effect reversal of the cross feed carriage.

Reversal is effected by means now to be described.

The push rod 388 has a collar or abutment I46 fixed on one end of it andan intermediate abut ment 346 clamped in anydesired position.

A tappet I43 fixed on the cross feed carriage 4| strikes the abutment346 as the carriage reaches the end of its return stroke.

A push rod I34 slides in guides I35 fixed to the front of the base 65,and in the guide 330 fixed at the rear of the base. It has collars I36and I 31 and springs I38 for holding it in a normal position. It has atooth 139 for engagement with two rather widely spaced teeth I40, I4I,on a rocker I42 oscillated by a lever I24. The push rod I34 has a collarI42 clamped on its rear end for engagement with the collar I46, and acollar 342 clamped in'any desired position for engagement by the tappetI43 when the cross feed carriage reaches the end of its advancing orfeeding stroke. I if Incidentally the lever I24 operates astop and startvalve, and-a lever I I I operates a valve controlling the hydraulicmechanism for raising and lowering the grinding wheel, these valvesbeing also fully described in the U. S. specification No. 2,585,376.

In operation of the machine, assuming'that the cross feed carriage M hascompleted an outward or return stroke, the tappet I43 will have engagedthe abutment 346 and shifted the push rod 388 so that the tappet 381will have shifted the piston valve 382 to the neutral position and thecross feed carriage will stop. When it is desired to make an inward oroperative stroke, the lever 42I is pulled so that the tappet 381 willshift the piston valve 382 so that the exhaust port 318 will be closedby the valve piston 385, the exhaust port 311 will be uncovered by thevalve piston 384 and the inlet port 316 will be uncovered by the valvepiston 383 to allow pressure fluid to pass to the port 315 but willprevent pressure fluid passing to the port 314. Consequently pressurefluid can pass by the pipe 312 to one end of the hydraulic cylinder 300,and exhaust fluid from the opposite end by the pipe 3' via ports 314 and311 and exhaust pipe 380 regulating valve 392 and pipe 391 to the sumpI80, with the result that the piston rod 30I of the hydraulic cylinderwill begin to advance the cross feed carriage 4|.

At the beginning of this advancing stroke of the cross feed carriage Mthe lever 402 will be depressed by the end of the cam 405, and beholding the piston valve 398 down so that the valve piston 500 will bein a position to allow fluid to pass fairly freely through the slot 406to the exhaust port 396 and thence through the pipe 391 to the sump I90.

As the cross feed carriage advances sufiiciently to allow the roller 404to rise up the upwardly curved part of the cam 405 the spring 40I raisesthe piston valve 338 and the valve piston 500 moves up and the slot 406offers a more restricted passage to the flow of exhaust fluid so thatthe speed of advance of the cross feed carriage, or rate of feed, isslowed down.

As the roller 404 rides down the downwardly curved part of the cam 405the lever 402 depresses the piston valve 393 of the regulating valve so6 that the exhaust flow through the slot 406 is increased andconsequently the rate of feed or advance of the cross feed carriage M isincreased. The reason for varying the rate of feed by the varyingcurvature of the cam 405 is that a work piece such as a mould boardvaries in length due to its peculiar shape and that the rate of feed ofthe cross feed-carriage should be slower when the traversing carriage ismaking long'strokes and quicker when it is making short strokes.

The shape of the cam 405 is therefore determined to suit the shape ofthe work piece to be ground.

1 When the cross feed carriage reaches the end of its advancing orfeeding stroke the tappet I43 strikes the collar 342 on the push rod I34and moves it so that the collar I42 strikes the collar I46 and shiftsthe push rod 388 whereby the tappet 386 will shiftthe position of thepiston valve 382 of the control valve 400 back into the neutral positionand thus stop the feeding of the cross feed carriage. To bring the crossfeed carriage back to the outward position, the lever 42I is pushedinwardly, thereby pushing the push rod 388 towards the rear of themachine. As the push rod 388 moves, the tappet 336 will shift theposition of the piston valve 382 so that the pressure fluid will passthrough the pipe 31I to the hydraulic cylinder and fluid is exhaustedfrom it via pipe 312, :pipe38l freely through th gate valve 393 to thesump I90.

At the same time the valve piston 384 closes the exhaust. port. 311. ofexhaust the return :stroke of the cross feed carriage is much quickerthan the advance or feeding stroke, g

In Figures 2 and 9 the push rod I34 is shown connectedby a chain I44 toan electric solenoid I54; the chain-passing over a guide pulley I45. AsdescribedinPatent No. 2,585,376, in. case of anemergency, a switch isclosed whereupon the solenoid 254 is energized and pulls the push rodI34 which moves the rocker I42 to operate the stop and start valve andthereby out off the supply of pressure fiuid. In the present instance,this operation of the push rod I34 also moves the piston valve 382 ofthe control valve 400 to a neutral position.

We claim:

1. A grinding machine of the, character referred to for grinding mouldboards of plough bodies and other articles of varying profile, saidmachine comprising a base, journal means pivotally mounted on said base,a spindle journalled in said means with its axis substantiallyperpendicular to the axis of the pivotal mounting of said journal means,a grinding wheel mounted on said spindle, a cross-feed carriage mountedon said base for movement substantially axially of and toward and awayfrom said grinding wheel, a traverse table mounted on said carriage fortraverse movement transverse to the motion of said carriage, a worktable pivotally mounted on said traverse table for tilting about an axissubstantially perpendicular to the axis of said wheel, means on saidcarriage and connected to said traverse table for reciprocating saidtraverse table relative to said grinding wheel, means on said traversetable and connected with said work table for tilting said work tableduring reciprocation of saidtraverse table, a double acting hydrauliccylinder mounted on said stationary support and having a piston rodconnected with cross feed carriage for reciproeating said cross feedcarriage toward and away from said grinding wheel, means for controllingOwing to the free flow v speed regulating valve on said base andoperated by said cam and connected with the other exhaust pipeconnection which is used during the forward feed stroke to ensure a slowcontinuous feed of said cross feed carriage.

2. A grinding machine as specified in claim 1, said speed regulatingvalve comprising a valve casing having an exhaust port, a reciprocatoryvalve piston in said casing for controlling said port, said valve pistonhaving a tapered passage for cooperation with said port, and a spindleprotruding from said valve casing, a spring for pressing said spindleupwards, a lever for depressing said spindle downwards, said leverhaving a roller, a curved cam on the cross feed carriage for engagingwith said roller, and means for rotating said spindle for varying therelation of said tapered passage and said cooperating exhaust port forregulating the effective area of exhaust.

3. A grinding machine comprising a base, a grinding wheel journalled onsaid base, a crossfeed carriage mounted on said base for movement towardand away from said wheel in a direction substantially axially of saidwheel, a traverse table mounted on said carriage for traverse movementtransverse the movement of said carriage, a work table for supporting awork piece in position relative to said grinding wheel, said work tablebeing pivotally mounted on said traverse table for tilting movementabout an axis substantially perpendicular to the axis of said wheel, hy-

draulic cylinder means on said base and connected with said cross-feedcarriage for advancing and retracting said carriage toward and away fromsaid whee1, a control valve for said hydraulic cylinder means andincluding a valve body and a valve member movable in said body, meansbetween said cross-feed carriage and saidvalve member for actuating saidvalve member upon completion of each stroke of movement of saidcross-feed carriage, acamon said cross-feed carriage, and cam followingmeans on said base engageable with said cam and connected with saidcontrol valve to regulate the speed of fluid flow through said valve inaccordance with the particular portion of thestroke of movement ofsaidcross-feed carriage. g

4. A grinding machine as defined in claim 3 wherein said control valvehas two exhaust ports respectively opened by said valve member duringthe advancing and retracting strokes of movement of said carriage, saidport that is open during the retracting stroke of said .carriage beingfree to exhaust to permit a quick return of said carriage, and said camfollowing means comprises a cam follower actuated speed regulating valveconnected with said port which is open during the advancing stroke ofsaid carriage to regulate the speed of forward movement of saidcarriage.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,316,221 Conradson Sept. 16, 1919 2,019,487 Ernst Nov. 5,1935 2,127,877 Maglott Aug. 23, 1938 2,150,091 Alvord Mar. 7, 19392,214,394 Wood Sept. 10, 1940 FOREIGN PATENTS Number Country Date489,193 Great Britain July 21, 1938

